Scaffold



c. c. DROEGER ETAL 2,593,122

SCAFFOLD April 15, 1952 Filed Deo. 27, 1946 2 SHEETS-SHEET l @i ALV HM' April 15, 1952' c. c. DROEGER ETAL scAFFoLp Filed Deo. 27, 1946 2 SHEETS-SHEET 2 wwwa/QQ.,

Csm. C,

Patented lApr. 15, 1952 SCAFFOLD I Carl C. Droeger, Greeniield, and Eugene J. Meloy and William Clark Reggie, Indianapolis, Ind., assignors to Baker-Roos, Inc., Indianapolis, Ind., a corporation of Indiana Application December 27, 1946, Serial No. 718,716

3 claims. 1

Our invention constitutes an improvementI on the scaffold disclosed in the prior United States Letters Patent No. 2,335,046 to Carl C. Droeger. The scaffold unit disclosed in that Droeger patent is of the knock-down type and comprises a;U

pair of vertical, ladder-like end frames which are held in parallel spaced relation by a horizontal bracing structure serving as a support for a platform, the bracing structure being adjustable on the end frames to support the platform at various' elevations.

It' is an object of the present invention to improve the construction ofthe Droeger scaffoldunit and to simplify and lessen the cost of its manufacture. A further object of the invention is to increase the flexibility of the unit by adapting a `plurality of units for superposition one on the other and by providing for the rigid interconnection of laterally spaced units. Still another object of the invention is to prevent accidental disassembly of each scaffold unit such as might result from a reversal of load.

'In carrying out our invention, we form the en d frames of each scaffold unit as ladders having parallel, vertically extending uprights; and` we provide such uprights at their ends with provisions by which the end frames of a plurality'of scaffold units may be supported one on the other and held in proper condition of alignment. The

ladder-interconnecting structure of each unit comprises a pair of horizontal side rails each having at its ends provisions by which it may be releasably connected to corresponding uprights of the end frames of the unit. The uprights of each end frame are arranged to receive both side rails which are normal to the plane of the end frame and other rails which are coplanar with the end frame, so that such other rails may be used to interconnect a pair of laterally spaced scaffold units.

\ The accompanying drawings illustrate our invention:

Fig. l is a perspective view of an assembly of scaffold units; Fig. 2 is a fragmental side elevation of thescaffolding; Fig. 2a is a horizontal section on the line 2a--2a of Fig. 2; Fig. 3 is a vertical section on the line 3-3of Fig. 2;,l Fig. 4 is a. fragmental vertical section of the joint between uprights of superposed scaffold units; Fig. 5 is a vertical section through the lower end of the lowermost unit; Fig. 6 is a horizontal section on the line 5-6 of Fig. 5; Fig. '7 is a perspective view showing an assembly of scaiold units of modied construction; Fig. B is a side elevation in partial section of the scaiTold unit illustrated vin Fig. 7; andv Fig. 9 is a horizontal section on the line 9-9 of Fig. 8.

`In the construction illustrated in Figs. l to 6, each scaiold unit comprises a pair of end frames in the form of ladders having vertical uprights I5 interconnectedV by vertically spaced. horizontally extending rungs I6. Each side memberv I5 is conveniently formed of sheet-metal bent along parallel lines into a4 generally square. `hollow cross-section, the edges of the metal,which either abut as shown at I1 in Fig. 2a oroverlap as indicated at I'I in Fig. 6, being secured together as by welding. The rungs I6 may be metal rods, tubing, or pipe of circular cross-section and are permanently connected, as by Welding, to the two side members I5 of the end frame.

In addition to two of the end frames `I5--IIS, each of the scaiold units includes a pair of side rails 2li to the ends of which are secured shoes or guides 2|.` The guides 2| extend normally to the associated side rail 20, and thestructureis desirably stiiened by obliquely extending brace members 22. Conveniently, the side rails 20, guides 2 I, and braces 22 are secured in assembled condition by welding. Each guide 2| comprises a pair of perpendicular iianges 2,3 and `2li adapted to engage two adjacent side faces of one of the vertical uprights I5 of an end element. l u

` For the purpose of p-roviding for the interconnection of side rails to the end frames atvarious elevations, the outer wall of each upright I5 -iS provided with a series of equally spaced openings 25, and the overlying flange 24 of each guide 2| is provided with a pair of vertically spaced lugs 26 adapted to be received respectively in two of the openings 25. In the arrangement shown in Figs. 1 to 6, it is contemplated that the openings 25 will be generally rectangular in form and that each lug 26 will be provided with a downwardly projecting head 21 having an outwardly presented, inclined face 28. The openings 25 are large enough to receive the heads 21; and after the heads have cleared the openings, the side rail may be lowered to bringthe shanks of the lugs 26 into engagement with the lower edges of the holes 25, in which position the heads 21 will hold the uprights I5 seated in the guides 2l.

Each of the side rails 2li is desirably I i-shap'ed in cross-section to provide an inwardly extending iiange 30 and an upwardly extending ange 30. A platform 3| .rests on the anges 30 of opposed side rails, being confined laterally by the vertical flanges 30' of such side rails 20 and longitudinally by the flanges 23 of the guide members 2 I. Preferably, the platform 3I fits closely between the I through the lower faces of the lugs 26 and 10 the lower ends of the openings 25. Thus, such loads tend to maintain the lug seated against the lower ends of the openings-'25,1inlwhiclrposition the heads 21 preventseparation*orthev en'd frames from the guides 2|. Under-certain con` Q15 ditions, however, as when an out-board load'of suflicient magnitude is appliedito'lonebf the end frames, the unit may tend to tilt about the bottom of such end .frame to raise the other `end frame from the floor. Under such circum- "stances,"` the f force of gravity acting. onV the elevated end frame would tend tol causeit to. move Y"downwardly" in its associated guide-2 |to bring the fopenings25into. a postionsuch thatthe heads theelevated end frame mightV thus become: sep- "aratedifromTthe-associatedsiderails. 'To prevent r-:any such separation upon a reversalfofload we guide-flange 24 fand-which is 1 'provided vadjacent its otheror ffreeend with -a' projection '36 :positionedto'- enter oneoflthe'openings 25'whenithe "lugs 26' areseated in the position shown in' Fig.3.

4 tances between them and the respectivelyadjacent ends of the uprights will be an integral multiple of the hole-spacing, any side rail may be placed at such an elevation that its associated guide 2| will overlap two superposed end frames with the upper lug received in an openingl25 of one upright-.andthe lower lug received 4in ari/opening 25 of thefsubjacenti upright, as indicated in Fig. 3. In this manner, the joint between superposed uprights may be stiffened and .an assembly of superposed scaffold units strengthened.

.-By..providing;=aisecond series of openings 25' lligl) similar-'to the openings 25 but located in ya tubeewalhperpendicular to that in which vthe-openings;2^5"are located, tie-rails 20' may be `employed;vto;interconnect laterally spaced scafvfold units in the manner indicated in Fig. l. The rtie-'rails 20 are generally similar to the cross rails 20 and are provided with upright-engaging .'guidesiZ I zhaving; luga@ like the .lugs 26, receiv- "Z'Ifofi the `lugs 42rcould pass through. them,v and C25 zfold-of :adequate strength and stability can be ',:ableLintheaopenings5f. :'Byxemploying a series of-.laterally `spaced :scaiold4 unitsv interconnected by tierrai'ls`2'0. and by Ysuperposingr tiers of :similarly: interconnected scaffoldunits, a rigid sca-f- :erected to-a` greatheight.

:11n-.the .modiedform of theainvention illusthe end: frames are'made'of circular tubing or pipe instead of being made from sheet-metal as inthe construction aboveldescribed. v:Like'the -uprightsxlthe uprights |I51are provided with -a seri-esf'vertically spacedopenings I25xadaptfed .tor receive :lugs 'I 25 i:on: guides I2 I which v are :securedvto` the; ends off` side frai'ls I 20' and braced vbyracesIZZ. :In `this instance, however, the

`.openings .|25 fare :of 'fkeyehole `shape with their large-ends! at theitop;v and. the: lugs I 2 5 are-pro- 1Normally,:'the'-leaf spring 35f'lies parallelrto the 40 :Vdedwithfcircular heads- ITI-which' are; adapted 36 inwardly in 'such position that it `may rengage the upper end ldftheopening 25' in which :itfiswreceived and limit relative upward `move- 'tofenter the-larger iendsof the openings |25 but which are too large .to be :removed through the smaller,` lower lendsof `such openings. Vv'As -a result. the normal .downwardload#applied to Ithe side position` which-locks the upright` I |-5 to'the guide |2I. :Zr-leaf spring-|35-provided With-a projection |35 `may'loe employed to preventsuch up- "vvard movementcof the `:sided-.ail as would be .toiwitlidrawthe projection v315 from theI opening 50 lneCeSSely t0 free the lugs |25 from the Openings 2 5h and permit 'f such upward movement vof the #Side railiandg guide -2| asis `necessary to` bring upright. Desirably, the bushings- 40 are located 60 thus. making itlpossible to Vlocatexbot'hrside and interflttmg Apins :4| fand 'bushings 40 to align superposed end iframes a Avertically extending series of scaffold units maybe-erected, as indicated'm Fig. "1.

JAswill-bepbvious Vin vorder -for the lugs 25 to enter-anypair-'of spaced holes -25 and hold 70A the? platform 30at1any desired-elevation it will beinecessary for the distance between the lugs itohe"an'integral multiple of the distance Vbetween "adjacentmoles 25. 'By locating the endholes25 f-erally spaced-scaffold "units lmay be intercon- Anected in the'samefmanner as that indicated in Fig. l. 'As' will becIearrOm'Fig. .9, theguides I2| may have an angular extent of less than90,

tie rails |20 and |20' at the same elevation.

`Instead f of :employing tie rails |20 to inter- VVconnect directly two laterally. spaced scaiold units, asA theltie rails '20' are'usedrin Fig. 1,".the scaffolding maybe extended-horizontally by interconnecting -'aunit, or a vertical column of units, with-single uprights-2|5 orwith columns of such uprights. 'Where a stillgreater horizontal extent is desired, uprights 2|5 may be interposedbetweentwo horizontally spaced units,

as indicated in Fig. 7, and connected to the end frames of `both such units by tie rails |20'. Where single` uprights 2 I5 are used, they are desirably interconnected bysi'dera'ils I 20. If' -thefsidera'ils |20 and the tie rails |20 are of inverted T-section, as shown in Fig. 9, the platform within a scaffold unit can be extended by additional platform-sections I3I supported on the flanges vof the tie rails |20.

The rungs I 6 of the end frames serve not only to interconnect the two uprights, I5 or I I5, of such end frame but also provide a means enabling ascent to an elevated platform. The rungs I6 of each end frame are equally spaced to facilitate their use as a means of ascent; and to maintain uniform rung-spacing between superposed end frames, the sum of the distances between the end rungs and the respectively adjacent ends of theV end frames is equal to the spacing between adjacent rungs within the end frame.

While we have shown the end framesl in the drawings as of uniform length, it is to be understood that end frames of different lengths may be provided and may be incorporated in a single scaffold. End frames of relatively short length may be used where a roof or ceiling would prevent the use of end frames of normal length at the top of a column of units. Short end frames may also be used to support a side rail or |20 at such an elevation above the platform I3I that it will serve as a guard to protect a workman on the platform against falling therefrom.

We claim as our invention:

l. In knock-down scaffolding, a plurality of end frames each including a pair of spaced uprights rigidly interconnected by a plurality of spaced horizontal rungs, said uprights being provided at their ends with complementary provisions adapted to intert when two end frames are superposed and to hold the superposed end frames in alignment, horizontal side rails for interconnecting the uprights of opposed en d fra-mes, each of said side rails being provided at its ends with vertically extending guides adapted to receive the uprights of different end frames, each of said uprights being provided with a vertical series of equally spaced openings, each of said guides having a pair of vertically spaced lugs adapted to be received in interlocking relationship in two of said openings to prevent separation of the guide from its associated upright, the sum of the-respective distances between end openings of the series and the adjacent ends of the upright being equal to an integral multiple of the distance between adjacent openings, whereby the lugs on any guide can be received respectively in openings of superposed uprights.

2. In knock-down scaffolding, a plurality of end frames each including a pair of spaced uprights, means rigidly interconnecting the uprights of each end frame, said uprights being provided at their ends with complementary provisions adapted to interfit when two end frames are superposed and to hold the superposed end frames in alignment, horizontal side rails for interconnecting the uprights of opposed end frames, each of said side rails being provided at its ends with vertically extending guides adapted to receive the uprights of different end frames. each of said uprights being provided with a vertical series of equally spaced openings, each of said guides having a pair of vertically spaced lugs adapted to be received in interlocking relationship in two of said openings to prevent separation of the guide from its associated upend openings of the series and the adjacent ends Y of the upright being equal to an integral multiple of the distance between adjacent openings, whereby the lugs on any guide can be received respectively in openings of superposed uprights.

3. A knock-down scaffold unit, comprising a pair of end frames each including two spaced tubular uprights of rectangular cross-section interconnected by a plurality of horizontal rungs, one wall of each upright being normal to said rungs and secured thereto, a pair of side rails extending between said end frames, each of said side rails having at its ends vertical guides removably receiving corresponding uprights of the two end frames, each of said guides having surfaces engaging different sides of the received upright, each of said uprights being provided with a first vertically extending series of equally spaced openings in the wall opposite that to which the rungs are secured and being provided in one of the other upright-walls with a second vertically extending series of equally spaced openings, each of said guides having a pair of vertically spaced, headed lugs adapted to be received in any of a plurality of pairs of the openings in said`first series, tie rails similar to said cross rails and provided with lugs co-operating with the openings of said second series for interconnecting a pair of laterally spaced scaffold units, said openings and lugs'being so shaped and arranged that the heads of the lugs may be inserted in two of the openings by movement normal to the upright and then engaged with the inner surface of the upright-wall by downward movement of the associated guide relative to the upright, the heads on said lugs when engaged with the inner surface of the upright-Wall lying wholly within the tubular upright.

CARL C. DROEGER.

EUGENE J. MELOY.

WILLIAM CLARK ROGGIE.

REFERENCES CITED The following references are of record in the le of this patent: I

UNITED STATES PATENTS Number Name Date 99,246 Shannon Jan. 25, 1870 598,289 Hagan Feb. 1, 1898 991,565 Valentine May 9, '1911 1,351,053 Macklem Aug. 31, 1920 1,422,246 Adams July 11, 1922 1,691,976 Kramer Nov. 20, 1928 1,918,116 Mansfield July 11, '1933 2,127,280 Zimbolist Aug. 16, 1938 2,185,948 Pimm Jan. 2, 1940 2,308,832 Roney et al Jan. 19, 1943 2,311,988 Lavn Feb. 23, 1943 2,316,952 Halferty Apr. 20, 1943 2,335,046 Droeger Nov. 23, '1943 2,363,382 Attwood Nov. 21, 1944 2,435,461 Parker Feb. 3, 1948 2,468,186 Du Perret Apr. 26, 1949 FOREIGN PATENTS Number Country Date v20,731 Great'Britain 1900 

